Steam-operated hot water heater with conical coil



y 1'959 J. A. PHILLIPS, JR 3,456,620

STEAM-OPERATED HOT WATER HEATER WITH CONICAL COIL Filed March 12, 1968 2 Sheets-Sheet 1 Fig./ 18

7 5 l k V I 4o; 24

,0 lab M James A. Phi/lips, Jr.

INVENTOR.

WWW 8% July 22, 1969 J. A. PHILLIPS, JR

STEAM'OI'LLRA'IED HOT WATER [IEA'ILR Wllll UONICAL COIL 2 Sheets-Sheet :1

Filed March 12, 1968 Fig.3

Fig. 4

INV/INTOR.

Mafia. WW 3m James A. Phillips, Jr.

United States Patent 3,456,620 STEAM-OPERATED HOT WATER HEATER WITH CONICAL COIL James A. Phillips, Jr., Salisbury, Md., assignor of thirty percent to James A. Phillips, Sr., and Leah M. Phillips, jointly, Quantico, Md.

Continuation-impart of applications Ser. No. 431,018, Feb. 8, 1965, and Ser. No. 616,915, Feb. 17, 1967. This application Mar. 12, 1968, Ser. No. 712,512

Int. Cl. F221) 1/08 U.S. Cl. 12232 14 Claims ABSTRACT OF THE DISCLOSURE A water heater employing a steam heating coil which absorbs and uses the latent heat of the steam passing through the coil for heating water in which the coil is immersed. The coil in one embodiment defines a cylinder and is provided with bafiles and in other embodiments the convolutions of the coil define a cone to facilitate stacking of multiple coils in the same water heater to facilitate construciton of a water heater with only a single coneshaped coil or a water heater with multiple stacked coneshaped coils. In another arrangement, a single cone-shaped coil is used but the steam supply is introduced at two points along the length of the coil rather than at only one point at the end of the coil to increase efliciency of the Water heater. The coil is provided with an unrestricted outlet which does not include a steam trap or other restriction heretofore employed in all steam pressure equipment. The steam supply is through an orifice of a predetermined size which may be adjusted or varied.

This application is a continuation-in-part of my copending application Serial No. 431,018, filed Feb. 8, 1965, now Patent No. 3,399,718, issued Sept. 3, 1968, and Serial No. 616,915, filed Feb. 17, 1967, now Patent No. 3,387,591, issued June 11, 1968.

The present invention relates to water heaters and more particularly to water heaters employing a steam heating coil which absorbs and uses the latent heat of the steam passing through the coil to heat the water in which the coil is immersed.

The steam hot water heater of this invention operates on low or high pressure steam. This steam hot water heater is designed primarily for industrial use where large quantities of water may be withdrawn from the hot water heater at one time. The hot water heater of this invention is capable of producing large volumes of water at a constant temperature. It is capable of supplying large volumes of water as desired economically and feasibly.

In the hot water heater of this invention steamis supplied to a coil, which winds helically through the central part of the hot water heater, from a steam supply outside of the hot water heater. The steam passes from a steam supply into the coil within the hot Water heater through a solenoid steam valve. This solenoid steam valve is electrically connected to a thermal responsive Aquastat which is responsive to temperatures within the hot water heater. The solenoid steam valve is adapted to be opened or closed by the Aquastat according to demands made by the temperature of the water within the hot water tank. When the temperature of the water within the hot water tank reaches a predetermined degree (e.g., 190 F.) the Aquastat will respond to these thermal conditions and break the circuit between the Aquastat and the solenoid steam valve thereby closing the steam valve and cutting off the supply of steam to the coil. Therefore, the temperature of the water within the hot water tank is in effect controlled by the steam, and conversely the flow of steam through the hot 3,456,620 Patented July 22, 1969 water heater is controlled by the temperature of the water within the hot water heater.

It is a further object of this invention to provide a switching means for controlling the pressure of the Water within the hot water heater in addition to the conventional pop oif valves found in other hot water heaters. The pressure switch will cut all electricity off when the pressure within the water tank goes 10 pounds above the normal city water line pressure. The electric solenoid valve is designed to close and shut off the supply of steam to the interior of the hot water heater when the electricity thereto is cut ofi. Therefore, the supply of steam is shutdown when the pressure within the hot water tank reaches a pressure of 10 pounds above the line pressure, or when the water within the hot water heater reaches a predetermined temperature (e.g., F.) The solenoid steam valve is designed to open when the water within the hot water tank drops to a temperature below a predetermined degree. When this occurs the Aquastat in response to such temperature conditions will be efiected to open the solenoid steam valve through the electrical circuitry connected therewith.

Steam enters the heating coil tubing in the hot water heater adjacent the bottom thereof at whatever steam pressure is available to the device. As the steam passes through the coils of the tubing within the tank body of the hot water heater the steam will condense into water, however, the pressure of the steam behind the condensate forces the condensate to the top of the hot water heater and out of the end of the tubing to be returned to a place where the condensate can be reheated, but before the water or condensate discharges from the end of the tubing to thereafter be returned, further steam condensation will take place and this will be adequate to hold back the steam, which is coming into the coil at the steam inlet thereby preventing such steam from just blowing through the coils. This condensate will form a self-replenishing water column in the tubing. This water column as previously explained will be of sufficient head to hold the steam back and eliminate the steam trap that is used in other pressure steam applications. The coil within the hot water heater and the water held within the tank are in thermal heat exhcange relationship so that the water or condensate that emits from the end of the tubing will be substantially lower than the temperature thereof when it enters the steam inlet. Since a steam trap is not employed in this invention steam will be allowed to rapidly enter the coil through the solenoid steam valve, and will form condensate within the coil thereby forming a water column which will be of suflicient head to hold the steam back as it comes into the coil, however the steam coming into the coil will have sufiicient pressure behind it to continuously exhaust the water or condensate from the coil out of the other end of the tubing into the return without any obstructions. The water or condensate returned from the hot water heater of this invention will be piped back to the steam generators or to boiler storage tanks to be reused and reheated to provide a steam thereby saving heat loss which would be involved in merely wasting the steam condensate.

As is well known, the conventional method of heating water by the use of steam is by employing a device utilizing a steam trap. Such a device employs a closed heating coil containing the heating medium which separates it from the heating medium with the closed coil terminating in a steam trap. A substantial part (approximately 39%) of the latent heat of the steam is normally discharged through the steam trap and lost via radiation venting to the atmosphere thus materially reducing the efficiency of the output of the water heater. This invention eliminates the steam trap entirely and substitutes therefor an impeding water column which is induced and controlled by the size and length of the closed coil tubing, location of the Aquastat and capacity of a governing orifice with a resultant improvement in efficiency. A substantially higher percentage of the total output of the steam boiler can be used by the present invention which results in a substantial saving to the operator because it requires less fuel.

The steam coil may be in the form of a cylinder or in the form of a cone tapering inward as it approaches the top of the tank which eliminates need for bafiles, is easier and less expensive to fabricate and can be readily lifted off the form on which it is fabricated thus enabling the conical coils to be stacked. This enables the output to be varied by stacking a plurality of conical coils in a single heater.

Still another important object of this invention is to provide a conical steam coil in which the steam is introduced at two points along the length thereof employing a reverse venturi at the top connection and a straight venturi at the second or lower connection.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming .a part hereof wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a vertical sectional view of the water heater illustrating the associational relation of the components;

FIGURE 2 is a sectional view of a water heater employing a single conical heating coil;

FIGURE 3 is a vertical sectional view similar to FIGURE 2 illustrating a single conical coil with two steam inlets associated therewith;

FIGURE 4 is a vertical sectional view similar to FIGURES 1-3 illustrating a plurality of stacked coils arranged in a single heater;

FIGURE 5 is a detail view of the reversed venturi at the upper steam connection employed in FIGURE 3; and

FIGURE 6 is a detailed view of the straight venturi used at the lower steam connection in FIGURE 3.

The steam hot water heater 10 of this invention in cludes a cylindrical tank 12 having a bottom 14 and a pressure dome 16 and a hot water outlet 18 for providing a conduit for the hot Water to be delivered from the hot water heater. A water inlet 20 is shown connected to the bottom of the tank 12 for replenishing water into the hot water tank when hot water has been withdrawn therefrom. The water inlet 20 is preferably provided with a check valve (not shown), as generally required by plumbing codes, to prevent water from flowing out of the tank 12 by way of line 20.

A steam inlet 22 is connected to a generally helical coil arrangement 24 found within the hot water heater and disposed centrally thereof with the axis of the generally helical coil system being vertical. A return conduit 26 is provided in the upper reaches of the tank 12 and is connected to the upper portion of the coil 24 for removing condensate from the coil and returning the water or condensate back to a boiler system or steam generator for replenishing steam to the supply inlet 22. A solenoid steam valve 28 is connected to the inlet conduit 22 and is regulated by an Aquastat 30 which is connected to the tank 12 and is in thermal response to the temperature of the water therein by the use of a temperature sensing bulb 36. An electrical circuit 32 is seen connecting the solenoid steam valve 28 with the Aquastat 30 to thereby regulate the solenoid steam valve 28 in response to temperature changes in the tank. A pressure safety switch 34' is provided in the pressure dome and is responsive to the pressure within the dome and is designed to shutdown the system when the pressure within the dome exceeds 10 pounds above water supply line pressure. This pressure switch is used in addition to the conventional pop off valve 38 normally employed to release excess pressure in the tank to prevent rupture thereof.

The steam operated hot water heater of this invention operates as follows:

Water disposed within the hot water heater 10 and within the cylindrical tank 12 is in thermal exchange relationship with the helical coil 24 which winds up through the central body of the cylindrical tank 12. Steam is adapted to pass through the coil 24 by entering said coil through an inlet conduit 22 found at the bottom of the cylindrical tank 12. Passage of the steam flow through the coil 24 is regualted by the solenoid steam valve 28 which is open and closed in response to the Aquastat 30 also connected to the cylindrical tank 12. The Aquastat 30 is designed to maintain the water held within the hot water heater 10 within a prescribed temperature range. When the water within the hot water heater drops below a predetermined temperature the Aquastat will respond to thermal conditions within the tank 10 to open the solenoid steam valve 28. Once the solenoid steam valve is open steam will flow through the inlet pipe 22 and into the coil 24 and will pass upwardly within the coil 24 towards the top thereof. As the steam proceeds through its path within the coil 24 the steam will cause the temperature of the water within the tank 12 to rise since the steam and the water within the tank 12 are in thermal exchange relation. The temperature of the water within the hot water heater 10 will serve likewise to cool the temperature of the steam rising in the copper coil 24. This will serve to eventually cause condensation of the steam to form condensate within the coil 24 as the steam drops below its vaporization temperature. The latent heat released by the steam when being condensed will be conducted to the water within the tank 12 thereby raising the temperature of this water. The condensate will form a water column within the coil 24. This condensate will be continuously forced upwardly in the coil 24 to a position at the top thereof where the condensate may be returned through the return conduit 26 to the steam generator units employed to produce the steam used. A sufiicient quantity of condensate will be held within the coil 24 to provide a head therein sufficient to contain the steam within the coil and prevent the steam from blowing through the coil and out into the return pipe 26. As the temperature of the water Within the tank 12 reaches a predetermined degree within the temperature range prescribed, the Aquastat 30 which is in thermal responsive relation with temperature changes within the tank 12 as indicated at '36 will respond and break the circuit to the solenoid steam valve 28 thereby closing the solenoid steam valve and shutting down the supply of steam to the coil system 24.

In the event that the water temperature within the hot water tank 12 should exceed the predetermined temperature and reach a condition which is considered dangerous, as to the pressure within the tank, a pressure responsive switch 34 would be operated by the pressure within the tank and will break the electrical circuit to cut down the supply of electricity to the Aquastat 30' thereby shutting down the system and closing the solenoid steam valve 28 until pressure within the tank 12 has been lowered below the operating pressure of the switch 34. A plurality of horizontally disposed fiat baflle plates 40 may be secured to the interior of the tank 12 to force the water entering through the pipe 30 to follow a sinuous path around the spirals of the helical coil as the Water flows toward the outlet 18.

Also disposed in the steam supply line 22 is a changeable orifice 42 which controls the flow rate of steam to the coil 24. This orifice will vary in size depending upon the capacity of the boiler and other equipment associated therewith. By changing the orifice, the rate of production of heated water to a given temperature may be increased thus enabling the unit to be employed with boilers of various capacities. The orifice 42 is placed in the steam line just before entering the electric solenoid valve 28 and this orifice will be varied depending upon the horsepower rating of the boiler, the degree of temperature rise and the gallons per hour desired.

FIGURE 2 illustrates an improved embodiment of the invention including a tank 44 having a bottom 46 and a domed top 48 or the like with it being pointed out that the structure of the tank itself is substantially the same as that described in FIGURE 1. In this construction, the steam coil 50 defines a cone with the lowermost convolution being larger than the uppermost convolution of the coil, thus, the steam coil is generally conical and tapers inwardly as it approaches the top 48 of the tank 44. The convolutions of the coil are retained and supported by straps 52 which may be conventional fiat straps of copper or similar material and cross supporting rods or frame members 54 are provided for anchoring the lower ends of the straps 5'2 and also anchoring the lowermost convolutions in place. The upper ends of the straps 52 may be secured to the top 48 of the tank 44 with the inlet to the coil being at the bottom thereof and the outlet being a the top. As illustrated, the inlet line 56 may enter through the top as may the outlet line 58. The control apparatus such as disclosed in FIGURE 1 will also be employed with this construction.

The use of the conical configuration of the coil eliminates the need of bafiles such as the bafiles 40 illustrated in FIGURE 1 in the tank since the convergency of the loops of the coil 50* toward the top of the tank forces the water to pass over the loops of the coil without need for forcing the water inward by the bafiles. Secondly, the conical coil 50 is much easier and less expensive to fabricate then the cylindrical coil illustrated in FIGURE 1 since the conical coil may be easily and readily lifted off of the form on which it is fabricated. In addition, the conical configuration permits stacking of the conical coils when assembled in a tank as described hereinafter and also permits stacking of the coils for reduction of storage space and space required in transport of the coils themselves.

FIGURE 4 illustrates a hot water heater including a tank 60 with a bottom 62 and a domed top 64. This construction illustrates a plurality of stacked conical shaped coil arrangements as designated by numerals 66, 68 and 70, each of which has an inlet line communicated with one end thereof and an outlet line communicated with the other. The coils are retained in supported position by supporting straps 72 and supporting rods or braces 74 to retain the coils in place within the tank. In this construction, the coils each receive steam from the inlet and each discharge condensate and this construction enables an increase of capacity of the water heater to whatever degree desired. In other words, the conical heating coil may be considered a module which can be duplicated and assembled to whatever multiple desired. For example, any number of coils may be arranged within the tank with each of the conical coils having the same advantages as described previously in conjunction with the single coil.

FIGURES 3, 5 and 6 disclose another embodiment of the invention including a tank 76 provided with a bottom 78 and a domed top 80 which is the same construction as disclosed in FIGURE 2. In this construction, there is provided a conical coil 82 tapering to the top and provided the numeral 98. The inlet line 92 at the upper end of the and supported by supporting members 86 and straps 88 all of which are the same as in FIGURE 2. The coil 82 has an inlet line 90 provided with two inlet branches 92 and 94 respectively. The upper convolutions of the coil 82 are separate from the lower convolutions with the outlet line 96 of the upper convolutions being communicated with a lower venturi generally designated by the numeral 98. The inlet line 92 at the upper end of the upper convolutions of the coil 82 is communicated with an upper venturi generally designated by the numeral 100*.

The construction of the upper venturi 100' as illustrated in FIGURE 5 and may be considered a reversed venturi inasmuch as it includes a T-fitting 10'2 receiving the inlet flange pipe 92 and being disposed in the inlet line 90. The area of the T where the branch line joins the through line is provided with an inclined bafile 104 which is inclined toward the inlet end of the inlet pipe or toward the direction of flow. The center of the baffle 104 is provided with an opening 106 through which a portion of the steam will pass with the remainder of the portion being diverted through the branch line 92 connected with the upper convolutions of the coil 82.

The lower venturi 98 includes a similar T-fitting 108 which has the branch thereof receiving the discharge line 96 from the upper convolutions of the coil 82 with the other part of the T having the steam inlet line 90 and the branch line 94 communicated therewith respectively for communication with the lower group of convolutions of the steam coil 82. An inwardly inclined baffle 108 inclined away from the direction of flow is provided at the juncture between the inlet end of the T-fitting and the branch line 96 so that the steam passing through the venturi 108 will pick up the condensate or condensate and steam being discharged from the upper convolutions of the steam coil.

The point of connection of the steam line 94 is approximately one-third of the distance from the top of the conical steam coil. This arrangement increases the efficiency and permits reduction in the amount of heating surface below standards of the industry which is understood to be 1.5 square feet of heating surface to raise one hundred gallons of water F. in one hour. Inasmuch as it has been discovered that most of the transfer occurs in the top part of the coil, this arrangement of providing the two steam inlets into the coil permits use of'the bottom convolutions of the coil for further heat transfer rather than merely using the bottom part of the coil as a conduit for steam and condensate which has already been cooled as it passes through the upper convolutions. Thus, by introduction of steam at these two points, the efiiciency of the heat transfer is increased thus enabling reduction and surface area of the coil.

With the supporting straps attached to the convolutions of the coils and fixed to the top of the tank, the entire coil assembly may be removed when removing the top cover. The bottom of the coil assembly includes a substantially horizontal loop attached to the cross-frame or rod which is not attached to the tank itself and is slightly smaller than the diameter of the tank thus centering the coil therein and enabling removal out through the top along with the top member. Thus, the entire interior assembly is removed when the removable top is lifted off. Where multiple or stacked coil arrangements are employed, the bottom coil is centered by the use of the X- frame and the upper coil or coils are nested onto the bottom coil and permanently attached to the supporting strips where they are in contact. In addition, extra support strips may be extended down from the removable top cover and may be attached to the bottom loop of each coil.

Also, the multiple or stacked coil assembly can utilize the split inlet or venturi type of arrangement for introducing steam into the coils or they may use the non-venturi type coils.

The water heater of the present invention is capable of delivering a greater volume of heated water in a more efficient and economical manner and employs steam from various types of existing steam generators or boilers. The water heater is ready to operate in only several minutes from a cold start and is compact and safe in operation and requires no cleaning, flushing or the like. The heater works only on demand and heats water only as required thus eliminating waste. The particular materials, pipe size and other structural details may vary for each individual installation to satisfy the requirements thereof.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In a heat exchanger, the combination of a tank, a coil comprising a plurality of spaced loops within said tank, a steam inlet pipe extending to said tank and a thermal responsive steam valve connected to said steam inlet pipe for controlling the flow of steam therethrough, said steam inlet pipe being connected to said coil for conducting steam from said inlet pipe to said coil, and an unrestricted outlet pipe connected to said coil for conveying condensate away from said heat exchanger, said coil having convolutions thereof progressively decreasing in diameter from the bottom to the top thereof thereby defining a conical configuration to force the water passing over the coil to come into contact with all of the surfaces thereof.

2. The structure as defined in claim 1 wherein said tank includes a removable top, and means supporting said coil solely from the top for removal therewith.

3. The structure as defined in claim 2 wherein said means supporting the coil from the removable top includes a plurality of depending strap members attached to the convolutions of the coil, and a frame means at the lower end of the strap for centering the lower end of the coil in the tank.

4. The structure as defined in claim 1 together with at least one additional coil having the convolutions thereof defining a cone disposed in nested relation to the first coil for increasing the capacity of the heater.

5. The structure as defined in claim 4 wherein the multiple of coils are supported from the top of the tank, said top being removable to enable removal of the coils with the top.

6. The structure as defined in claim 5 wherein the lowermost of the multiple of coils is supported from a frame means centering the lowermost coil in the tank, said frame means being removable with the removable top.

7. In a heat exchanger, the combination of a tank, a coil comprising a plurality of spaced loops within said tank, a steam inlet pipe extending to said tank and a thermal responsive steam valve connected to said steam inlet pipe for controlling the flow of said steam therethrough, said steam inlet pipe being connected to said coil for conducting steam from said inlet pipe to said coil, and an unrestricted outlet pipe connected to said coil for conveying condensate away from said heat exchanger, said steam inlet pipe being provided with two branches communicated with the steam coil at spaced points along the length thereof thereby introducing steam into the coil at spaced points therealong.

8. The structure as defined in claim 7 wherein one of the branches of the steam inlet pipe is connected to an end of the coil and provided with a reverse venturi therein, the other branch of the steam inlet pipe being connected to an intermediate portion of the steam coil and provided with a straight venturi.

9. The structure as defined in claim 8 wherein the convolutions of the steam coil between the two inlet points are independent of each other with the discharge end of the portion of the steam coil between the two inlet points being communicated with the straight venturi.

10. The structure as defined in claim 7 wherein said coil has the convolutions thereof progressively decreasing in diameter from the bottom to the top thereof thereby defining a conical configuration to force the water passing over the coil to come into contact with all of the surfaces thereof.

11. The structure as defined in claim 10 wherein said tank includes a removable top, and means supporting said coil solely from the top for removal therewith.

12. The structure as defined in claim 10 together with at least one additional coil having the convolutions thereof defining a cone disposed in nested relation to the first coil for increasing the capacity of the heater.

13. A liquid heater comprising a tank having liquid inlet means and liquid outlet means therein for enabling flow of liquid therethrough, a heating coil disposed in said tank in heat exchange relation to the liquid, said coil including a tubular member having an inlet means communicating with a source of steam and an unrestricted outlet means for steam condensate whereby the heat of vaporization of the steam is given up to the liquid with the steam condensate exiting from the outlet means, said outlet means urging no steam trap or other restriction, whereby steam Will be allowed to rapidly enter the coil through the inlet means, and will form condensate within the coil thereby forming a water column which will be of sufficient head to hold the steam back as it comes into the coil, the steam coming into the coil having sufficient pressure behind it to continuously exhaust the water or condensate from the coil at the other end of the tubular member into the outlet means without any obstructions, the water or condensate returned from the liquid heater being piped back to the steam generators or to boiler storage tanks to be reused and reheated to provide steam thereby saving heat loss which would be involved in merely wasting the steam condensate.

14. The structure defined in claim 13 wherein said inlet means for the steam includes a valve controlling the inlet means for the steam when the temperature of the liquid is elevated to a predetermined level, said inlet means including an orifice of predetermined dimension to control the rate of flow of steam into the coil, said outlet means being free of restriction to reverse flow required to compensate for reduction of volume of steam in the coil as it is condensed thereby avoiding collapse of the tubular member due to a vacuum.

References Cited UNITED STATES PATENTS 1,159,775 11/1915 Kerr. 2,430,837 11/1947 Tutein 16539 X FOREIGN PATENTS 816,894 7/1959 Great Britain.

CHARLES I. MYHRE, Primary Examiner 

